This "Science note" arose out of practical work involving the dilution of ethanoic acid, the measurement of the pH of the diluted solutions and calculation of the acid dissociation constant, K[subscript a], for each diluted solution. The students expected the calculated values of K[subscript a] to be constant but they found that the…

End-pipe corrections seldom come to mind as a suitable topic for an introductory physics lab. Yet, the end-pipe correction formula can be verified in an engaging and inexpensive lab that requires only two supplies: plastic-tube toys called boomwhackers and a meter-stick. This article describes a lab activity in which students model data from…

This paper presents a simplified approach for the application of material efficiency metrics to linear and convergent synthesis plans encountered in organic synthesis courses. Computations are facilitated and automated using intuitively designed Microsoft Excel spreadsheets without invoking abstract mathematical formulas. The merits of this…

Establishes a rationale for teaching population genetics to students and inservice biology teachers. Suggests strategies for introducing students to the Hardy-Weinberg principle. (MDH)

Describes the construction of a wave generator used to review the algebraic relationships of wave motion. Students calculate and measure the weight needed to create tension to generate standing waves at the first eight harmonics. (MDH)

Presents an activity in which students construct model hot air balloons to introduce the concepts of convection current, the principles of Charles' gas law, and three-dimensional geometric shapes. Provides construction and launching instructions. (MDH)

Describes the modern hot-air balloon and the physics of ballooning. Proposes that students construct their own hot-air balloon and presents an experiment calculating the time needed for a balloon to rise to the ceiling of a gymnasium. (MDH)

Describes two simple methods of error analysis: (1) combining errors in the measured quantities; and (2) calculating the error or uncertainty in the slope of a straight-line graph. Discusses significance of the error in the comparison of experimental results with some known value. (MDH)

Describes a first-year laboratory course designed to fulfill laboratory objectives of reinforcing lecture material, teaching experimental methodology, developing hands-on skills, and imparting a sense of error. The course's six segments examine: digital electronics with students building a photogate timer; error analysis; linear accelerated…